The BBC’s Yogita Limaye, who was in Nepal’s mountains when the latest earthquake struck, tweeted: “We’re safe. Did feel the earth shake for quite a long time. Saw dust and stones flying off mountain near by.”

She told BBC World News: “The earth shook and it shook for a pretty long time.

“I can completely understand the sense of panic. We have been seeing tremors: it’s been two-and-a-half weeks since the first quake. But this one really felt like it went on for a really long time. People have been terrified.”

It struck at a depth of 15km (9.3 miles), according to the US Geological Survey – the same depth as the April 25 quake. Shallow earthquakes are more likely to cause more damage at the surface.

Tuesday’s earthquake is likely to be one of the largest to hit Nepal, which has suffered hundreds of aftershocks since 25 April.

The 7.3 quake was followed 30 minutes later by another large aftershock, centred on the district of Ramechhap, east of Kathmandu, that had a magnitude of 6.3.

Analysis: Jonathan Amos, BBC News, Science Correspondent

By any stretch, a magnitude-7.3 quake is a big one. It’s not quite as big as the quake on 25 April (7.8), which was 5.5 times more energetic, but it’s a major tremor nonetheless.

Since 25 April, the immediate analysis had suggested that more activity on the fault was possible because the previous event had not ruptured all the way to the surface. That meant some of the strain built up in the rocks over the years had not all been released.

One has to hope that the buildings which were damaged last time have been felled in subsequent aftershocks, or have been put out of bounds. This will limit the casualties this time. But further landslides and avalanches in the mountainous terrain are a persistent risk.

And, of course, another big tremor does nothing for the frayed nerves of an already anxious population.